Device for ventilating wave-guide systems



DEVICE FOR VENTILATING WAVE-GUIDE SYSTEMS Filed April 1. 1957 AGENUnited States Patent DEVICE FOR VENTILATING WAVE-GUIDE SYSTEMSApplication April 1, 1957, Serial No. 649,733

Claims priority, application Netherlands April 19, 1956 2 Claims. (Cl.S33-98) This invention relates to devices for Ventilating waveguid,systems.

For Wave-guide systems in permanent arrangements such as, for example,in radar installations or beam transmitter stations, it is frequentlynecessary to take steps in order that dried and/or heated air or aneutral gas, for example nitrogen, may be blown into the waveguidesystem to avoid corrosion and condensation of Water vapour. The gascontainer or the drying and/or heating installations of the air to beblown into the system must be connected somewhere at the beginning orthe end of the wave-guide system. The couplings concerned are requiredto affect the electric field configurations as little as possible. Thismay be achieved in known manner by choosing the coupling holes or slotsto be comparatively small with respect to the wavelength of the waves inthe wave-guide. For very high frequencies such, for example, ascorrespond to millimetre waves, the coupling holes must, however, be sosmall as to constitute a considerable resistance to flow, so thatinsufiicient gas or air can flow through the wave-guide.

In the device according to the invention for Ventilating wave-guidesystems, a directional coupling known per se is provided, at least onecoupling opening being provided in the adjacent side-walls of the waveguides such that wave energy supplied via a given extremity of one waveguide is discharged completely through a given extremity of the otherwave guide, and conversely. Furthermore,

the other extremity of one Wave guide is coupled to guides G1 and G2 hasprovided in it a coupling opening KG, which is so proportioned that waveenergy supplied via the end A is transferred completely via the couplingopening KG to the wave guide G2 and may be discharged via the end B. Thecoupling factor of such a directional coupling may be equal to unity ina comparatively broad frequency range, for example a relatve variationof 15%, that is to say that substantially no energy is transferred vto.the arms C and D of the direc- Patented Jan. 5, 1960 ICC tionalcoupling and these arms thus are electrically neutral. taining a gasflow in the wave-guide system, for example a gas ycontainer or an airpump, if desired further means being provided for drying and/or heatingthe blow air. The arm D of wave guide G1 is shut off in a gas-tightmanner by means of a wall or piston Z, which wall also preventsescapement of any high-frequency energy via the arm D. The blow air isthus led via the arm B to the aerial and via the coupling opening KG andthe arm A of wave-guide G1 to the transmitter. As a matter of fact, thecoupling opening KG has only a very small resistance with respect to theair ow. In order to prevent wave energy from escaping via the arm C orleaking in via the pump, it may be desirable for the dimensions of thepipe concerned to be chosen such that travelling waves cannot occurtherein, which on the other hand has the disadvantage that theresistance to ow s increased. Consequently, the wave pipe C ispreferably not narrowed, but a thin metallic partition S is arranged atthe centre thereof, as shown in the drawing.

What is claimed is:

l. A device for Ventilating a waveguide system, comprising first andsecond hollow pipe waveguides, means for supplying electrical waveenergy into an end of said first waveguide, means providing at least onehollow electrical coupling from a side of said first waveguide to a sideof said second waveguide thereby providing a directional couplingwhereby said wave energy is discharged at an end of said secondwaveguide, means connected to the remaining end of said second waveguidefor inducing gas into said system, means closing the remaining end ofsaid first waveguide in a gas-tight manner, and means preventing escapeof said wave energy through said remaining end of said second waveguidecomprising a metallic partition centrally disposed in said remaining endof said second waveguide and extending longitudinally therewith.

2. A device for Ventilating a waveguide system, comprising first andsecond hollow pipe waveguides positioned side-by-side along at least aportion of the lengths thereof thereby providing a common sidewall,means for supplying electrical wave energy into an end of said firstwaveguide, means connected to a corresponding end of said secondwaveguide for inducing gas into said system, said common sidewallcontaining at least one aperture thereby providing a directionalcoupling whereby said wave energy is discharged at the remaining end ofsaid second waveguide, means closing the remaining end of said firstwaveguide in a gas-tight manner, and means preventing escape of saidwave energy through said corresponding end of said second waveguidecomprising a metallic partition centrally disposed in said correspondingend of said second waveguide and extending longitudinally therewith.

References Cited in the file of this patent UNITED STATES PATENTS2,709,241 Ribiet May 24, 1955 2,721,309 Seidel oct. is, s 2,783,449Loviek Peb. 26, 1951 The arm C is connected to a device for mainv

